package com.example.aop;

import com.example.annotation.RedisLockLock;
import com.example.utils.RediLock;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;
import org.springframework.stereotype.Component;

import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;

/**
 * @author ChenXiaoBin
 * on 2019-09-09
 */
@Aspect
@Component
public class RedisLockInterceptor {

    private static final Integer MAX_RETRY_COUNT = 10;
    private static final String LOCK_PRE_FIX = "lockPreFix";
    private static final String TIME_OUT = "timeOut";

    @Pointcut("@annotation(com.example.annotation.RedisLockLock)")
    public void redisLockAspect(){}


    @Around("redisLockAspect()")
    public Map<String, Object> lockAroundAction(ProceedingJoinPoint proceeding) throws Exception {
        //获取redis锁
        Map<String, Object> getLockResult = this.getLock(proceeding,0,System.currentTimeMillis());
        return getLockResult;
    }



    /**
     * 获取锁
     * @param proceeding
     * @return
     */
    private Map<String, Object> getLock(ProceedingJoinPoint proceeding,int count,long currentTime){
        //获取注解中的参数
        Map<String, Object> annotationArgs = this.getAnnotationArgs(proceeding);
        String lockPrefix = (String) annotationArgs.get(LOCK_PRE_FIX);
        long expire = (long) annotationArgs.get(TIME_OUT);
        String key = this.getFirstArg(proceeding);
        String lockName = lockPrefix+"_"+key;
        String value = String.valueOf(currentTime);
        if (RediLock.tryLock(lockName, 5)) {
            return this.buildSuccessResult();
        } else {
            //获取锁失败,为防止其它线程正在设置过时时间时误删，添加第一个条件
            return this.buildGetLockErrorResult("请重试！！！");
        }
    }


    public Map<String, Object> getAnnotationArgs(ProceedingJoinPoint proceeding) {
        Class target = proceeding.getTarget().getClass();
        Method[] methods = target.getMethods();
        String methodName = proceeding.getSignature().getName();
        for (Method method : methods) {
            if(method.getName().equals(methodName)){
                Map<String, Object> result = new HashMap<String, Object>();
                RedisLockLock redisLock = method.getAnnotation(RedisLockLock.class);
                result.put(LOCK_PRE_FIX,redisLock.lockPrefix());
                result.put(TIME_OUT, redisLock.timeUnit().toSeconds(redisLock.timeOut()));
                return result;
            }
        }
        return null;
    }



    /**
     * 获取第一个String类型的参数为锁的业务参数
     * @param proceeding
     * @return
     */
    public String getFirstArg(ProceedingJoinPoint proceeding){
        Object[] args = proceeding.getArgs();
        if(args != null && args.length>0){
            for (Object object : args) {
                String type = object.getClass().getName();
                if("java.lang.String".equals(type)){
                    return (String)object;
                }
            }
        }
        return null;
    }

    public Map<String, Object> buildSuccessResult(){
        Map<String, Object> result = new HashMap<String, Object>();
        //TODO
        //result.put("code", "1");
        result.put("msg", "处理成功");
        return result;
    }

    public Map<String, Object> buildGetLockErrorResult(String mes){
        Map<String, Object> result = new HashMap<String, Object>();
        //TODO
        //result.put("code", "9");
        result.put("msg", mes);
        return result;
    }
}
